Food Allergy Testing Frequently Asked Questions (FAQ)

ASCIA PCC Food Allergy Testing FAQ 2022191.9 KB

Q 1: What is required for an accurate diagnosis of food allergies?

Allergy is a science and evidence-based medical speciality, which relies on understanding the biological mechanisms of allergic disorders and proven, reliable tests and treatments.

This includes food allergy and severe allergic reactions (anaphylaxis) to foods:

• Allergic reactions to foods usually occur within a short time of ingestion of the food allergen, ranging from almost immediate to within an hour or two. Symptoms range from mild to moderate swelling of the face, eyes and lips, vomiting, diarrhoea and in the most severe cases, anaphylaxis.
• Allergy testing is not usually performed for symptoms such as stomach bloating or pain, which are rarely due to food allergy.
• Accurate diagnosis of food allergies requires an examination of a person’s clinical history, including symptoms that may be caused by food allergies, by a qualified medical practitioner. This is usually combined with results from proven, evidence-based and reliable allergy testing for individual food allergens, to confirm the diagnosis. Test results alone are not usually sufficient to make a diagnosis. For example, a positive allergy test does not always result in an allergic reaction when the food is eaten. 
• When considering food allergy tests, advice needs to be ‘evidence-based’. This means that there needs to be evidence that a particular test is reliable, based on suitable control groups in studies of people with similar conditions.

Q 2: Which food allergy tests are recommended by ASCIA?

The following proven, evidence-based allergy tests are recommended by ASCIA, when performed or ordered, and interpreted by a doctor who is trained in allergy diagnosis and management:

• Skin prick tests that measure allergen specific immunoglobulin E (IgE) antibodies for individual foods that are suspected to have caused an allergic reaction.
• Blood tests that measure allergen specific IgE antibodies for individual foods that are suspected to have caused an allergic reaction.
• Food allergen challenges that are medically supervised using published, consistent protocols. These are used to confirm or exclude food allergies, when performed for individual foods that have caused previous allergic reactions or are suspected to have caused an allergic reaction.

Test results should always be considered alongside a detailed medical history and physical examination by your doctor.

To assist with the medical history, the ASCIA Allergic Reactions Event Record form or Clinical History form can be used to record symptoms, features of reactions and factors that can affect severity of reactions.

These forms are available on the ASCIA website:

www.allergy.org.au/hp/anaphylaxis/anaphylaxis-event-record

www.allergy.org.au/hp/anaphylaxis/clinical-history-form-allergic-reactions

Q 3: Which tests are NOT recommended by ASCIA?

ASCIA does NOT recommend any of the following tests, which do not provide evidence based clinically useful results, are usually not relevant to the allergic condition, are a waste of resources (costs and time) and can lead to adverse outcomes including unnecessary and potentially harmful avoidance of foods:

• Tests for multiple food allergens, such as blood tests for food allergen mixes.
• Any tests that claim to ‘screen’ for food allergy, including genetic tests.
• Food allergy tests that are ordered online.
• Tests for Immunoglobulin G (IgG) to foods.
• Unproven, non evidence-based allergy ‘tests’ that are provided by some unorthodox/alternative practitioners. There is currently no stringent government regulation of these methods, which include Vega (electro-diagnostic), bioresonance, “cytotoxic”, Bryan’s or Alcat tests, hair analysis, VoiceBio, kinesiology and allergy elimination.

Q 4: What adverse outcomes can be due to allergy tests that are NOT recommended by ASCIA?

Adverse outcomes due to the use of the tests listed above that are NOT recommended by ASCIA include:

• Impact on employment and social functioning, due to unnecessary avoidance of foods.
• Impaired growth, food anxieties and malnutrition, due to unnecessary avoidance of foods.
• Delayed access to more effective diagnostic tests and treatments for allergic disorders.
• Lost productivity and income from inadequately controlled allergic disorders.
• Significant costs to person without allergies who is incorrectly diagnosed as having allergies.

Q 5: How is food allergy treated and why is food allergy testing important?

Food allergen avoidance is currently used to manage food allergy, so it is important that individual foods are identified through allergy tests, to avoid unnecessary avoidance of foods and adverse outcomes listed above.

In people who are at risk of anaphylaxis due to food allergy, it is especially important that individual foods are identified. Adrenaline (epinephrine) injectors are usually prescribed for treatment of life-threatening anaphylaxis, in case there is accidental exposure to confirmed food allergens.

Whilst oral immunotherapy (OIT) for food allergy is not currently a routine treatment in Australia and New Zealand, clinical research trials are being conducted to ensure that it is safe and effective.

Once OIT is in routine use, accurate and accessible food allergy testing, including food allergen challenges, will be vital to:

• Ensure that OIT is provided to people with confirmed food allergies; and
• Measure the effectiveness of OIT.

Q 6: What questions should you ask providers of unproven allergy tests and treatments?

In the absence of government regulation of unsubstantiated claims for unproven, non-evidence-based food allergy tests or treatments, patients should ask the same questions they ask about any tests or treatments before going ahead:

• What is the evidence it works?
• What are the risks and benefits?
• What might happen if I do not undertake this form of treatment?
• How much does it cost?
• Are there any side-effects?
• Why doesn’t my own doctor suggest this type of treatment?
• What are the qualifications of the practitioner recommending the treatment?
• Why can this one test of treatment detect or treat so many different problems?
• Is there a Medicare rebate for this test?

Q 7: Where can further information be obtained?

• ASCIA Information about allergy testing: allergy.org.au/patients/allergy-testing
• Organisations that support people with food allergy and their carers, including:

Allergy & Anaphylaxis Australia www.allergyfacts.org.au and Allergy New Zealand www.allergy.org.au

© ASCIA 2022

ASCIA is the peak professional body of clinical immunology/allergy specialists in Australia and New Zealand.

ASCIA resources are based on published literature and expert review, however, they are not intended to replace medical advice. The content of ASCIA resources is not influenced by any commercial organisations.

For more information go to www.allergy.org.au

To donate to allergy and immunology research go to www.allergyimmunology.org.au/donate